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Both the data and the code (Python) is here: https://zenodo.org/record/8065875 https://zenodo.org/record/8065875 That link came from the paper. Zenodo.org is

Both the data and the code (Python) is here: https://zenodo.org/record/8065875 https://zenodo.org/record/8065875 That link came from the paper. Zenodo.org is a open science site curated by NASA. The analysis is interesting. He is using Gaia space observatory data to identify "nearby" binary systems, filtering out those with a high likelihood of being compromised by additional bodies in the system, and those for which the bodies have poor mass estimates, then measuring the orbits of the remaining 26k systems that can be confidently projected to three dimensions and aren't too eccentric, etc. His results are that below some small level of gravitational acceleration (the stars are far apart with long orbital periods,) the orbits predictably deviate from Newtonian gravity, and that due to the small size of binary systems Dark Matter cannot be a factor. It's a Nobel prize winner if correct. Good old fashioned falsifiable Science: future data sets and peer review of the work will tell us. Too bad Gaia runs out of fuel in two years. The longer the data set the more confidence can be achieved in this sort of work. It's interesting that only the most recent of the so far three data sets from Gaia provides the data necessary (tangential and radial velocity,) to do this.

lou1306 3y ago
> curated by NASA. Er, it's actually maintained by CERN and funded by the European Union. NASA does somehow participate in it as part of its "Transform to Open Science" initiative.
V1ndaar 3y ago
> Zenodo.org is a open science site curated by NASA. No offense, but Zenodo is a CERN project. [0] [0]: https://about.zenodo.org/ https://about.zenodo.org/
- topspin 3y ago
  Ok. I was mislead by this, which appears as the first element of a carousel every time you load the Zenodo landing page: "Transform to OPen Science (TOPS) is a $40 million, 5-year mission, led by NASA's Science Mission Directorate's Open-Source Science initiative. Within the TOPS mission, NASA is designating 2023 as the Year Of Open Science, a community initiative to spark change and inspire open science... Curated by: nasatransformtoopen"
sebzim4500 3y ago
Do you know if Euclid will be able to collect this data after Gaia dies?
- topspin 3y ago
  Good question. I think perhaps not. This work is based on the data Gaia delivered in its most recent data release; the third so far. Only that release has provided both tangential and radial velocity of stars, which are crucial figures to compute the orbits of the binaries. This was done by correlating data collected simultaneously from the three instruments onboard Gaia. Does Euclid have the same three instruments or their moral equivalent? Will they operate Euclid such that they'll be producing similar data? I don't know. Even if there are equivalent capabilities, it's a different instrument, so the data will not simply slot in as the next tranche of observations.
philsnow 3y ago
I looked at the code for a bit, and it's just like most academic code I've ever seen/written: incredibly dense and cryptic. What is the likelihood that he has a transcription error somewhere? The average number of characters in the main file accel_ortho_wb.py is 52 characters per line (5 of the lines have over 300 characters). Aside from the question of whether the code is semantically/notionally correct, what about numerical precision issues? Python floats are 64-bit IEEE doubles. I've read through enough "floating point representations are fraught with peril" articles in the past to be default-skeptical of code written by people who haven't already run into--and addressed--computational issues specifically with them. I've never used numpy or done any hard mathematical analysis either in python or anything else. Does numpy somehow change the float type in python to use some other representation than doubles? How much precision is in a double? Is there "enough" for these astronomically large(/small) calculations? I guess a 52-bit mantissa can represent 2^52 = 4,503,599,627,370,496 ~= 10^15.65356. Is that ~"15 and a half digits" of precision? How does error propagate through all the calculations? edit: I don't want to just poke holes in this person's research. I'm crossing my fingers and hoping it's all correct both for their sake and for mankind's.
- taneq 3y ago
  If it's anything like the academic code I've seen, the likelihood approaches 2.

lou1306 3y ago

> curated by NASA. Er, it's actually maintained by CERN and funded by the European Union. NASA does somehow participate in it as part of its "Transform to Open Science" initiative.

V1ndaar 3y ago

> Zenodo.org is a open science site curated by NASA. No offense, but Zenodo is a CERN project. [0] [0]: https://about.zenodo.org/ https://about.zenodo.org/

topspin 3y ago
Ok. I was mislead by this, which appears as the first element of a carousel every time you load the Zenodo landing page: "Transform to OPen Science (TOPS) is a $40 million, 5-year mission, led by NASA's Science Mission Directorate's Open-Source Science initiative. Within the TOPS mission, NASA is designating 2023 as the Year Of Open Science, a community initiative to spark change and inspire open science... Curated by: nasatransformtoopen"

sebzim4500 3y ago

Do you know if Euclid will be able to collect this data after Gaia dies?

topspin 3y ago
Good question. I think perhaps not. This work is based on the data Gaia delivered in its most recent data release; the third so far. Only that release has provided both tangential and radial velocity of stars, which are crucial figures to compute the orbits of the binaries. This was done by correlating data collected simultaneously from the three instruments onboard Gaia. Does Euclid have the same three instruments or their moral equivalent? Will they operate Euclid such that they'll be producing similar data? I don't know. Even if there are equivalent capabilities, it's a different instrument, so the data will not simply slot in as the next tranche of observations.

philsnow 3y ago

I looked at the code for a bit, and it's just like most academic code I've ever seen/written: incredibly dense and cryptic. What is the likelihood that he has a transcription error somewhere? The average number of characters in the main file accel_ortho_wb.py is 52 characters per line (5 of the lines have over 300 characters). Aside from the question of whether the code is semantically/notionally correct, what about numerical precision issues? Python floats are 64-bit IEEE doubles. I've read through enough "floating point representations are fraught with peril" articles in the past to be default-skeptical of code written by people who haven't already run into--and addressed--computational issues specifically with them. I've never used numpy or done any hard mathematical analysis either in python or anything else. Does numpy somehow change the float type in python to use some other representation than doubles? How much precision is in a double? Is there "enough" for these astronomically large(/small) calculations? I guess a 52-bit mantissa can represent 2^52 = 4,503,599,627,370,496 ~= 10^15.65356. Is that ~"15 and a half digits" of precision? How does error propagate through all the calculations? edit: I don't want to just poke holes in this person's research. I'm crossing my fingers and hoping it's all correct both for their sake and for mankind's.

taneq 3y ago
If it's anything like the academic code I've seen, the likelihood approaches 2.